Orthopedic cast and method of constructing same

ABSTRACT

An improved plaster cast and method of preparing it from a plaster blank are provided by the present invention. A first sheet of resilient, deformable, water absorptive material is placed on a supporting surface and one or more plaster splints are aligned with the sheet. A second sheet of deformable, water absorptive, fibrous material is placed over the splints and the first sheet thus sandwiching the plastic splints between the two sheets. The edges of the sheets are joined together to form the casting blank. When used, the casting blank is saturated with water so as to wet out the plaster splints. To this end the highly water absorptive sheets facilitate transfer of the water to the plaster splints. The first sheet is characterized by a non-affinity for the plaster while the second sheet readily absorbs the plaster. The fibrous nature of the second sheet provides substantial reinforcing for the plaster as the latter hardens. After saturation of the blank, it is shaped around the portion of the body to be supported to form the cast. The cast may be held in place while drying by adhesive or elastic tape.

Lauber et al.

1 1 ORTHOPEDIC CAST AND METHOD OF CONSTRUCTING SAME [76] Inventors: Leo E. Lauber, 101 W. 10th St.,

Eudora, Kans. 66025; Ernest A. Cowden, 871 New Brotherhood Bldg., Kansas City, Kans. 66101 [22] Filed: June 28, 1974 [21] Appl. No.: 483,970

52] US. Cl 128/91 R [51] Int. Cl. A61F 5/04 158] Field of Search 128/91 R, 90

[56] References Cited UNITED STATES PATENTS 937,478 10/1909 Sims 128/91 R 1,131,295 3/191-5 Touart.... 128/91 R 2,530,986 11/1950 Moses [28/91 R 2,692,596 10/1954 Marconnet.... 128/91 R 2,960,984 11/1960 Parker 128/91 R 3,197,534 7/1965 Murray 128/91 R 3,373,741 3/1968 Hill et al. 128/90 Dec. 2, 1975 5? ABSTRACT An improved plaster cast and method of preparing it from a plaster blank are provided by the present invention. A first sheet of resilient, deformable, water absorptive material is placed on a supporting surface and one or more plaster splints are aligned with the sheet. A second sheet of deformable, water absorptive, fibrous material is placed over the splints and the first sheet thus sandwiching the plastic splints between the two sheets. The edges of the sheets are joined together to form the casting blank. When used, the casting blank is saturated with water so as to wet out the plaster splints. To this end the highly water absorptive sheets facilitate transfer of the water to the plaster splints. The first sheet is characterized by a nonaffinity for the plaster while the second sheet readily absorbs the plaster. The fibrous nature of the second sheet provides substantial reinforcing for the plaster as the latter hardens. After saturation of the blank, it is shaped around the portion of the body to be supported to form the cast. The cast may be held in place while drying by adhesive or elastic tape.

7 Claims, 9 Drawing Figures Sheet 1 of 2 3,923,049

US. Patent Dec. 2, 1975 ORTHOPEDIC CAST AND METHOD OF CONSTRUCTING SAME This invention relates generally to orthopedics and more specifically to an improved orthopedic cast and method of constructing same.

An improved plaster cast and method of preparing it are disclosed in application Ser. No. 437,522 filed Jan. 28, 1974. The invention disclosed in the referenced application utilizes a plurality of splints disposed between two sheets of deformable water absorptive material which are sealed at their peripheral edges to encase the plaster splints. This forms a casting blank which may be saturated with water and formed around a portion of the body to present a cast. The present invention is an improvement in the plaster cast and method of constructing same as disclosed in the referenced application.

It is therefore a primary object of the present invention to provide an improved plaster cast and method of constructing same wherein a plaster blank is utilized having at least one side constructed from a fibrous material with an affinity for moistened plaster whereby the plaster cast will be substantially reinforced by the fibers of the material when it hardens.

As a corollary to the above object, one of the objectives of the invention is to provide an immobilizing orthopedic plaster cast and method utilizing a plaster blank wherein one side of the blank is constructed from a fibrous material and the other side of the blank is constructed from a resilient cellular material having a nonaffinity for moistened plaster whereby the latter mentioned side will readily absorb and hold water and will form a resilient cushion for placing next to the wearers body.

Still another object of the invention is to provide a novel method of providing support in the lumbar region of the body wherein a plaster cast is utilized without the need to form a complete girth around the body of the wearer.

In the drawing:

FIG. 1 is a top plan view with portions broken away of a casting blank constructed according to the present invention for use in the inventive method of constructing a cast;

FIG. 2 is a perspective view illustrating how the casting blank would be placed to form a cast around the ankle and foot;

FIG. 3 is a side elevational view of the ankle and foot shown in FIG. 2 with the casting blank shaped to conform to the shape of this portion of the body;

FIG. 4 is a side elevational view of a portion of the elbow and upper and lower arm of a person encased within a cast constructed according to the teachings of the present invention;

FIG. 5 is a side elevational view, similar to FIG. 4, and illustrating a further step which may be utilized in constructing a cast according to the method of the present invention;

FIG. 6 is another side view of the arm and elbow shown in FIGS. 4 and 5 with the completed cast therearound;

FIG. 7 is a perspective view showing utilization of the cast formed according to the present invention to construct a cervical collar;

FIG. 8 is a side elevational view showing use of a cast constructed according to the present invention to form a lumbar support; and

FIG. 9 is an enlarged cross-sectional view taken along line 99 of FIG. 8.

Referring initially to FIG. 1, the present invention encompasses a novel casting blank 10 and a method of constructing it. A first sheet 12 of deformable water absorptive resilient material is placed on a working surface and trimmed to an appropriate size. Sheet 12 is preferably of a cellular construction, such as characteristic of foam rubber, for purposes to be made clear hereinafter. A number of plaster splints 14 are then placed over sheet 12 in general alignment with the latter. Each splint 14 is of a construction well known to those skilled in the art and normally comprises a layer of gauze cloth impregnated with the dry plaster ingredients. It is to be understood, however, that the term plaster splint as used in this application is intended to include any plaster-like material which will harden after water has been added, impregnated in a carrier such as the gauze cloth. While it is much preferred to utilize the plaster splints 14, for some applications it is possible to utilize dry plaster ingredients without the cloth carrier strips.

The number of plaster splints 14 may also be varied in accordance with the requirements for the particular cast being constructed. For most applications at least six of the splints 14 will be required to give the necessary support and additional splints may be utilized as needed.

A second sheet 16 of water absorptive deformable material is trimmed to the appropriate size and placed over the splints 14 on the first sheet. Sheet 16 is of a fibrous material, such as flannel cloth, having an affinity for moistened plaster. The sheets 12 and 16 are each of a size such that they present a surface area larger than the surface area of the splints 14 so that the edges of the sheets extend beyond the edges of the splints. In still other applications a construction utilizing two layers of cellular material may be desired.

Next, the edges of sheets 12 and 16 are joined together through use of a suitable adhesive, stitching, or other appropriate means. The completed casting blank 10 will thus comprise upper and lower layers of a deformable water absorptive material with at least one layer comprising a fibrous material and with a quantity of plaster sandwiched between the two layers. It has been found helpful to provide a centering ring 18 imprinted on the surface of one of the sheets to facilitate centering of a portion of the body such as foot 20 to be enclosed within the cast formed from blank 10.

When a cast is to be constructed from blank 10, the latter is saturated with water to activate the chemical reaction that will harden the plaster. Because splints 14 are enclosed within sheets 12 and 16, the amount of water utilized is easier to control. Generally, by submerging blank 10 for from 20 to 40 seconds (until the dry plaster becomes soft) the sheets 12 and 16 will become saturated and an adequate but not excessive quantity of water is available for splints 14. The fact that sheet 12 is of a cellular construction facilitates absorption and retention of the proper amount of water. Excess water is drained and pressed from blank l0 before the latter is moved into position for shaping around foot 20. The blank is shaped around the foot to conform to the shape of the latter by folding and kneading it into place. The completed cast as illustrated in FIG. 3 and designated by the numeral 22 will normally harden in ten minutes or less although this time may be accelerated by the application of warm air. The foam rubber material of sheet 12 will absorb water very rapidly thus facilitating wet-out of the plaster. The

foam rubber is also a material to which the plaster'will not adhere thus providing a comfortable resilient padding to be placed next to the wearers body. The flannel material, on the other hand, readily absorbs a quantity of plaster and the latter becomes embedded within the fibers of cloth. The fibers serve as reinforcing strands which significantly increase the strength of the completed cast. In other applications it may be desirable to construct both layers of flannel or other fiber material to enhance the strength even more. The one sheet of foam rubber is, however, generally preferred to enhance water absorption and make a comfortable padded surface to place next to the wearers body.

The blank is illustrated in FIG. 3 shaped into an elbow cast 24. It will generally be preferred for a cast formed from blank 10 to be wrapped with tape 26 to hold the cast in place while it is drying. Tape 26 may be an inelastic adhesive type or may comprise an elastic material commonly referred to as an elastic bandage. The tape remains in place after the plaster cast hardens and provides some additional support for the cast as well as a degree of protection against damage. As a final dressing for the cast, a stockinette 28 may be pulled over the tape 26. Manifestly, stockinette 28 may be easily removed and washed as required.

It will also be appreciated that the casting blank and method of the present invention may be utilized in the cervical area of the body to provide support and immobilization to a degree not heretofore possible with conventional collars, yet in situations which would not justify the placement of a conventional cast. To this end, FIG. 7 illustrates a blank 110 formed into a cervicalcast 122. Construction of blank 110 is identical to the blank 10 previously described. Also, formation of cast 122 is carried out utilizing the same method steps for the cast 22 as above described. Manifestly, the external stockinette and tape dressings have been omitted from cast 122 for purposes of illustration only.

Referring additionally to FIGS. 8 and 9, a belt designated generally by the numeral 30 comprises a pocket 32 spanning the lumbar region of a wearer of the belt and an elastic portion 34 for tightening the belt around the wearers body. Manifestly, it is desirable to construct elastic portion 34 in two sections, only one of which is shown in FIG. 8, for purposes of allowing ease in placement and removal of the belt.

Placed within pocket 32 is a casting blank 210 constructed in the same manner as the blank 10 above described with a first sheet 212 of resilient, cellular material and a second sheet 216 of flannel cloth. Sandwiched between the two sheets 212 and 216 is a layer of plaster 214.

In use, a lumbar support is provided by utilizing blank 210 and belt 30 by first saturating the blank with water in the same manner as described above for the construction of casts 22 and 122. Excess water is removed from the casting blank and it is then shaped to the lumbar region to be supported. Next, the shaped blank is removed from the body and cured to form a rigid cast. This rigid cast may then be placed in pocket 32 and belt 30 positioned around the wearer with the cast being lo cated in the lumbar region to be supported. This provides for a lumbar support having the advantages of a rigid plaster cast without the disadvantages of a cast which completely circumscribes the wearers body.

Having thus described the invention, we claim:

1. A method of constructing a casting blank from which a plaster cast for a portion of the body may be formed, said method comprising:

providing first and second sheets of deformable water absorptive material,

at least one of said sheets being fibrous material characterized by an affinity for moistened plaster,

the other of said sheets comprising a cellular material characterized by a non-affinity for moistened plaster;

placing a quantity of plaster between said first and second sheets; and

joining said first and second sheets together to enclose said plaster material therebetween.

2. A method as set forth in claim 1, wherein the step of placing a quantity of plaster comprises placing a quantity of plaster splints.

3. A casting blank for use in forming a plaster cast for a portion of the body, said blank comprising:

a first sheet of deformable water absorptive material;

a layer of plaster material disposed on said first sheet;

and

a second sheet of deformable water absorptive material disposed in overlying relation to said plaster material to sandwich the latter between said first and second sheets,

at least one of said sheets comprising a fibrous mate rial characterized by an affinity for moistened plaster,

the other of said sheets comprising a cellular material characterized by a non-affinity for moistened plaster,

said first and second sheets being joined together at their peripheral edges to enclose said plaster therebetween.

4. The invention of claim 3, wherein said plaster layer comprises a plurality of plaster splints.

5. A method of providing a lumbar support utilizing a casting blank formed from a quantity of plaster enclosed within a water absorptive deformable material, and a belt having a pocket for receiving a rigid cast, said method comprising the steps of:

saturating said blank with water;

shaping the saturated blank to the lumbar region to be supported;

removing the shaped blank from the body;

curing the saturated blank to fonn a rigid cast,

placing the rigid cast in said pocket; and

positioning the belt with the cast contained in the pocket tightly around the waist of the wearer with said cast disposed at approximately the same location as its location during said shaping step.

6. A method as set forth in claim 5, wherein said saturating step comprises submerging said blank in water for 20-40 seconds.

7. A method as set forth in claim 6, wherein is included, prior to said shaping step, the step of removing excess water from said blank. 

1. A method of constructing a casting blank from which a plaster cast for a portion of the body may be formed, said method comprising: providing first and second sheets of deformable water absorptive material, at least one of said sheets being fibrous material characterized by an affinity for moistened plaster, the other of said sheets comprising a cellular material characterized by a non-affinity for moistened plaster; placing a quantity of plaster between said first and second sheets; and joining said first and second sheets together to enclose said plaster material therebetween.
 2. A method as set forth in claim 1, wherein the step of placing a quantity of plaster comprises placing a quantity of plaster splints.
 3. A casting blank for use in forming a plaster cast for a portion of the body, said blank comprising: a first sheet of deformable water absorptive material; a layer of plaster material disposed on said first sheet; and a second sheet of deformable water absorptive material disposed in overlying relation to said plaster material to sandwich the latter between said first and second sheets, at least one of said sheets comprising a fibrous material characterized by an affinity for moistened plaster, the other of said sheets comprising a cellular material characterized by a non-affinity for moistened plaster, said first and second sheets being joined together at their peripheral edges to enclose said plaster therebetween.
 4. The invention of claim 3, wherein said plaster layer comprises a plurality of plaster splints.
 5. A method of providing a lumbar support utilizing a casting blank formed from a quantity of plaster enclosed within a water absorptive deformable material, and a belt having a pocket for receiving a rigid cast, said method comprising the steps of: saturating said blank with water; shaping the saturated blank to the lumbar region to be supported; removing the shaped blank from the body; curing the saturated blank to form a rigid cast; placing the rigid cast in said pocket; and positioning the belt with the cast contained in the pocket tightly around the waist of the wearer with said cast disposed at approximately the same location as its location during said shaping step.
 6. A method as set forth in claim 5, wherein said saturating step comprises submerging said blank in water for 20-40 seconds.
 7. A method as set forth in claim 6, wherein is included, prior to said shaping step, the step of removing excess water from said blank. 